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VARIABLE WIDTH SCANNING FILM VIEWER Filed Sept. 2, 1965 16 Sheets-Sheet 11 Fig. 15

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VARIABLE WIDTH SCANNING FILM VIE WER Filed Sept. 2, 1965 16 Sheets-Sheet 14 LAE HOME LIGHT JIO PIO TS l4 L3 R4 CENTER SENSING a'mn zw Mal SWITCH ps3 R LATERAL CENTER FL66KT E5TN P| :JOYSTICK ASSY. 1 DIRECTION I ssnsms SWITCH M32 +Y L Y M29 LIMIT SWITCHES +Y M30 CR|4 cms :50 v 0.0. LATERAL CR MOTOR CR? J6 P6 T5 '7 FIELD F g. /8

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March 26, 1968 W. D. JOHNSON T AL VARIABLE WIDTH SCANNING FILM VIEWER l6 h ets-Sheet 15 Filed se t. 2, 1965 March 26, 1968 w. D. JOHNSON ET AL 3,374,707

VARIABLE WIDTH SCANNING FILM VIEWER Filed Sept. 2, 1965 16 Sheets-Sheet l6 62 x om moss. 268 I2.

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United States Patent 3,374,707 VARIABLE WIDTH SCANNING FILM VIEWER William D. Johnson, Santa Clara, Vincent Grippi, Jr.,

Novato, and Edward C. Aguilar, Berkeley, Calif., assignors to Houston Fearless Corporation, doing business as Nuclear Research Instruments, a division of Houston Fearless Corporation, a corporation of California Filed Sept. 2, 1965, Ser. No. 484,579 8 Claims. (Cl. 88-28) ABSTRACT OF THE DISCLOSURE An apparatus for viewing continuous-reel film transparencies at different magnifications and at varying film speeds consisting of a viewing screen; a light source; reel means for positioning the film in the optical path between the light source and screen; means for driving the reel means rotationally and laterally; a plurality of projection lenses movable into the optical path; a plurality of condensing lenses movable into the path of the light from the light source in varying combinations; and power and control means for moving the projection lenses, the condensing lenses, the light source and the reel means.

and improved variable width scanning film viewer. 4

Another object is to provide a viewer of the character described which will permit viewing of the film at different magnifications without a substantial change in the level of screen illumination.

A further object is to provide a viewer as described which is adaptable for showing the film emulsion side up or down.

Still another object is to provide a viewer as described which can be constructed relatively inexpensively from a minimum of reliable components for moving a reel of film in either direction at infinitely varying speed ranges; changing speeds smoothly and at infinitely varying accelerations responsive to operator control.

A still further object of the present invention is to provide a device which can rotate the film, move it laterally for magnified viewing of all parts of the film and clamp the film for fine focusing.

Another object is to provide a viewer in which the film can be quickly and easily loaded and unloaded.

A further object is to provide a viewer of the character described for moving the film from a position at rest to a pre-selected initial speed which is slower than previously possible in film viewing mechanisms and without noticeable uneven starting of the film.

Still another object of the present invention is to provitle a device having infinitely variable scan and slew modes of film travel.

Another object of the invention as above described is to provide a film viewer adaptable for receiving and accommodating film of variable widths and thickness.

The invention possesses other objects and features of advantage, some of which of the foregoing will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of this specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

Referring to the drawings (15 sheets) FIGURE 1 is a side elevation view of the variable width scanning film viewer constructed in accordance with the present inven- 3,374,707 Patented Mar. 26, 1968 tion with portions broken away and some parts removed for purposes of clarity.

FIGURE 2 is a top plan view of the device shown in FIGURE 1 on a reduced scale with parts removed for purposes of clarity and some moving parts shifted and rotated for purposes of understanding.

FIGURE 3 is a front elevation view of a portion of the device on an enlarged scale taken substantially along the line 3-3 of FIGURE 1.

FIGURE 4 is a side elevation view of the device shown on an enlarged scale and taken substantially along the line 44 of FIGURE 2.

FIGURE 5 is a front elevation view of a portion of the device shown on an enlarged scale with some moving parts rotated for purposes of understanding and taken substantially along the line 55 of FIGURE 1.

FIGURE 6 is a top plan view of the device shown on an enlarged scale with portions removed for purposes of clarity and taken substantially along the line 6-6 of FIGURE 1.

FIGURE 7 is a side elevation view of the device on an enlarged scale with portions removed for purposes of clarity and taken substantially along the line 7-7 of FIGURE 6.

FIGURE 8 is a side elevation view of the device shown on an enlarged scale with portions broken away and other portions removed for purposes of clarity and taken substantially along the line 88 of FIGURE 2.

FIGURE 9 is a front elevation view of a portion of the device shown on an enlarged scale and taken substantially along the line 99 of FIGURE 2.

FIGURE 10 is a perspective view of a portion of the device with some parts in an exploded position for purposes of clarity.

FIGURE 11 is a top plan view of a portion of the device shown on an enlarged scale and taken substantially along the line 11-11 of FIGURE 1.

FIGURE 12 is a side elevation view of the device taken substantially along the line 1212 of FIGURE 11.

FIGURE 13 is a side elevation view of a portion of the device shown on an enlarged scale and taken substantially along the line 1313 of FIGURE 1.

FIGURE 14 is a side elevation View taken substantially along the line 14-14 in FIGURE 13.

FIGURE 15 is an operational schematic of the device as characterized above.

FIGURE 16 is a functional wiring diagram of the film drive mechanism constructed in accordance with the present invention.

FIGURE 17 is a functional wiring diagram of the film clamping mechanism constructed in accordance with the present invention.

FIGURE 18 is a functional wiring diagram of the lateral movement mechanism of the present invention.

FIGURE 19 is a functional wiring diagram of the lamphouse movement mechanism constructed in accordance with the present invention.

FIGURE 20 is a functional wiring diagram of the stage rotation mechanism constructed in accordance with the present invention.

FIGURE 21 is a functional wiring diagram of the condensing lens mechanism constructed in accordance with the present invention.

FIGURE 22 is a functional wiring diagram of the projection lens mechanism constructed in accordance with the present invention.

The present invention consists briefly of a rear view translucent image viewing screen 11; a light source; first means for positioning a film transparency in the optical path (designated by arrow 9) between the light source and the screen; a plurality of projection lenses, here shown as lenses 3X, 6X, 12 and 30X; second means selectively positioning said lenses at predetermined positions in the optical path between the film and screen; a condenser lens mounted adjacent the film plane and in the optical path between the light source and the film plane, here consisting of condensing lenses 7 and 8; a plurality of auxiliary condensing lenses, here consisting of condensing lenses 3, 4, and 6; third means selectively positioning the auxiliary lenses at predetermined positions in the optical path between the condenser lens and the light source; and fourth means mounting the light source for movement on the optical path to predetermined positions to and from the film plane; and manually operated means for selectively energizing the second, third and fourth means for producing a plurality of magnifications of the film transparencies on the screen with substantially uniform illumination over the image on the screen for each of the magnifications.

The light source here consists of a tungsten filament projection lamp 18 mounted on a base 19 and enclosed by a housing having a front opening for receiving a Pyrex heat glass 21 and a 5 inch diameter fused quartz condensing lens 1 and a 7 inch diameter fused quartz condensing lens 2; both being' concave-convex.

Auxiliary condensing lenses 3, 4, 5 and 6 are 12 inch diameter crown glass. Lens 3 is of plane-convex configuration and is here mounted in one holder 23, Lens 4 is of bi-convex configuration and is here mounted in holder 24. Lenses 5 and 6 are mounted in a single holder lens 5 being convex-concave and lens 6 bi-convex. Lenses 7 and 8 are here made of crown glass and having a 15% inch diameter; lens 7 being bi-convex and lens 8 plane-convex.

A mirror 27 reflects the image of the projection lamp through condensing lenses 7 and 8; through the film and projection lenses to a second mirror 28 which reflects the film image upon the screen 11.

'Projection lens 3 is a 360 mm. F/5.6 and having a field of view 10" x 10'. Projection lens 6 is a 240 mm. F/5.6 and having a field of view of 5 x 5". Projection lens 12X is a 135 mm. F/3.5 and having a field of view of 2.5 x 2.5". Projection lens 30x is a 60 mm. F/2.0 having a field of view of l x l.

The viewing screen 11 is here a water-white on onequarter inch thick glass and having a size of 30" x 30". The illuminance at the screen is 30 foot-candles minimum on the operators side of the screen on axis with an open film gate at any magnification.

The first means above referred to for positioning the film in the optical path consists of a supply reel 30 and a take-up reel 31 for receiving a length of film.

The second means above referred to consists briefly of a turretframe 33 upon which the projection lenses are pivotally mounted; lens 3 being mounted on arm 34,

lens 6 on arm 35 and lens 12x on one end of a V- shaped arm 36 with lens 30X on the other arm 37.

The third means referred to above consists briefly of three horizontal shaft members 39, 40 and 41 respectively slidably receiving lens holders 23, 24 and 25.

The fourth means above referred to consists of a pair of rails 43 and 44 for slidably receiving the lamphouse housing 20.

The manually operated means above referred to com sists of an upright member or joystick 46 mounted on the control panel 26 in front of the screen 11.

An important feature of the present invention is the capability of viewing a film transparency at any one of four different magnifications and to change magnifications by depressing a single pushbutton switch. Actuation of the magnification switch causes three independent operations to be carried on simultaneously and automatically; viz. movement of the lamphouse, interchanging of the condenser lenses and selection of t F 9 Projection lens.

Lamphouse movement Lamphouse 20 is reciprocally moved along rails 43 and 44 by a slow-speed DC. motor 45 with integral gear reduction which rotates a leadscrew 29 connected to a follower nut 47 mounted on the lamphouse. A cam plate 48 mounted on the lower side of the housing actuates linearly aligned microswitches M35, M36, M38 and M39 which control the lamphouse motor for positioning the lamp for the different magnifications.

Referring to FIGURE 19; lamphouse movement functional diagram.

The lamphouse turn-on procedure for energizing the lamphouse circuit for controlled operation is as follows: Assume that the lamphouse is at the (30X) position and M39 is actuated. When the machine is turned on, 24 volts is applied through latch bar switch No. 1, PB6-1, PBS-1, PB41, M39, and contact K29-4 to energize K28. K28-2 operates, applying volts through K29-2 to the motor. The lamphouse moves toward the motor and consequently backs off M39. With M39 deactuated, 24 volts is applied through K283 to energize K29. K29-2 transfers, applying a small positive voltage (dropped by resistor R28) to the motor, and the lamphouse travels slowly forward to reactuate M39. With K29-4 transferred, the circuit through M39 and K28 is open and K28 is deenergized. Contact K28-2 drops .to open the circuit to the motor and lamphouse travel comes to a stop. K29 remains energized through transferred contact K2 91.

Four pushbuttons are provided on the control panel corresponding with the different magnifications. In FIG- URE 19, the 3x magnification corresponds with push button PB41, 6 magnification corresponds with push button PBS-1, 12X magnification corresponds with push button PB6-1 and 30x magnification corresponds to the pushbutton P B7-1. Each of the pushbuttons are mechanically connected .to one another so that depressing one button automatically deactivates the other pushbutton. In addition, each of the buttons is mechanically connected to both of the latch bar switches No. l and 2 so that as the particular pushbutton is depressed, both latch bar switches are momentarily transferred. All switches and microswitches in the diagram are shown in the unactuated condition.

In operation, assuming that the lamphouse is at the (30X) position and it is desired to switch to the 12X magnification, the operation is as follows: As the 12X pushbutton is being depressed, latch bar switch No. 1 opens momentarily to de-energize K29, while latch bar switch No. 2 opens the circuit to the motor. When the pushbutton is completely depressed, the latch bar switches are again closed, and +15 0 v. is applied .to the motor through K293 and K28-2. The lamphouse travels forward (away from the motor) at fast speed. The 12 microswitch (M38) is actuated, 24 volts is applied through latch bar switch No. 1, and @364, through M38 and K29-4 to energize K28. 150 volts is applied to the motor through K29-2 and K282. The lamphouse travels quickly back toward the motor until M38 is deactuated. Then, 24 v. is applied through M38 and K28-3 to energize K29 and hold relay K28 energized. K291 latches relay K29 and K29-2 closes the circuit to apply +150 volts through resistor R28 to the motor. The motor senses the reduced positive voltage and the lamphouse moves slowly back to M38. M38 is again actuated; and since the circuit through K29-4 is now open, K28 is deenergized. K28-2 opens the circuit to the motor, and the lamphouse travel stops.

When the lamphouse is at the (12X) position and it is desired to switch to the 30X magnification, the circuit is energized as follows: As the 30X pushbutton is being depressed, latch bar switch No. 1 opens momentarily to de-energize K29, while latch bar switch No. 2 opens the circuit to the motor. When the 30X pushbutton is completely depressed, the latch bar switches are again closed,

and the 12X pushbutton (PB6-1) is completely released. 24 v. by way of 14-15, latch bar switch No. 1, P=B61, PBS-1, PB4-1 and the actuated 30 microswitch (M39), and K29-4 energizes K28. K28-1 transfers and latches The condenser lenses are automatically shifted in and out of the optical path when the magnification pushbuttons mounted on the control panel are actuated. The correlation between the pushbuttons on the control panel relay K28. K28-2 transfers providing the motor with and the electrical functional diagram shown in FIGURE 150 volts. The lamphouse travels back (toward the 21 is as follows: 3X is PB4-3, 6 is P-B53, 12 is BB6- motor) at fast speed, until M39 is deactuated. Then 3 and 30x is PB7-4 and PB7-3. The electrical circuit 24 volts is applied through M39 and K28-3 to energize shown in FIGURE 21 includes diodes D1 through D12 K29 and hold relay K28 energized. K29-1 latches relay and CR22 and CR23 placed in the circuit as shown. K29, and K29-2 closes the circuit to apply +150 volts 10 In operation in changing from a 30X magnification to through R28 to the motor. The motor senses a reduced a 12X magnification the lens changes would be as follows: positive voltage and the lamphouse moves slowly back Initially, the 30X pushbutton (PB7-4 and PB7-3) is dcto M38. M38 is again actuated; and since the circuit pressed and auxiliary condensing lenses are all in the opt-hrough K29-4 is now open, K28 is de-energized. K282 tical path, with microswitches M13, M15 and M17 actuopens the circuit to the motor and lamphouse travel stops. l5 ated. When the 12X button is depressed, the 30X button If it is desirable to move from the (30X) position to is released and the 12X button is mechanically latched. the 6X magnification, the movement is as follows: As A circuit is completed from the 150 volt supply through the 6X pushbutton is being depressed, latch bar switch P4-1, through PB7-4, P218,'P76, through diode D1 and No. 1 opens momentarily to de-energize K29, while latch through M14 to the 30X motor. Lens No. 3 is therefore bar switch #2 opens the circuit to the motor. When the 20 driven out of the optical path. The No. 3 lens holder pushbutton is completely depressed, the latch bar switches actuates M14 to break the 150 volt supply to the 30X are again closed, and +150 vo-lts is applied to the motor motor and stop for the travel of the holder. The No. 4, through K29-3 and K28-2. The lamphouse travels for- No. 5 and No. 6 lenses then provide the proper lightward (away from the motor) at fast speed. As the lampconvergence angle for the 12X magnification. house travels forwardly the cam actuates micro-switch In changing from the 12X to the X magnification M36 and 24 volts is applied through latch bar switch pushbutton 'PB6-3 is depressed and microswitches M15, No. 1 PB6-1, PBS-1, M36 and K29-4 to energize relay M17 and M14 are initially actuated. Depression of the K28. K2 82 transfers .to apply 150 volts to the motor. 30X button releases the 12X button and the 30X button The lamphouse reverses direction and travels quickly back is mechanically latched. +150 voltage is passed by way of toward the motor until M36 is deactuated. Then, 24 30 P444 through PB7-4, P2-18 and P7-6 through M13, volts is applied through M36 and K28-3 to energize K29, through diode D2 to the 30X motor. Lens No. 3 is thereand to hold relay K28 energized. K2 9-1 latches relay fore driven to a position in the optical path. The -No. 3 K29, and K294 closes the circuit to apply +150 volts lens holder actuates M13 to break the +150 volt supply through resistor R28 to the motor. The motor senses a to the 30X motor and stop further travel of the holder. reduced positive voltage and moves the lamphouse slowly The No. 3, 4, 5, and 6 lenses then provide the proper lightback to M36. M36 is again actuated; and since the circonvergence angle for the 30x magnification. cuit through K29-4 is now open, K28 is de-energized. In changing from the 30X magnification to the 6X K28-2 opens the circuit to the mot-or, and the lamphouse magnification the operation is as follows: Initially, the travel stops. 30X pushbutton (PB7-4, PB7-3) is depressed, and all of It is possible to switch from one magnification to any 40 the auxiliary condensing lenses are in the optical path other magnification and the lamphouse will move in a thus actuating switches M13, M15 and M17. Depressing manner similar to the examples above described. the 6 button releases the 30X button and the 6 button is mechanically latched. A circuit is completed from the Condenser lens 1s0 volt supply to P4-1, -PB7 4, P2-18, P7-6, through For 3 X magnification no auxiliary condenser lenses are Di d D1 d th h M14 t th 30 moton L N 3 n the p l w For X magnification lenses 5 and 6 is therefore driven out of the optical path and when it is mounted in holder 25 are in the Optical w For out of the optical path actuates M14 to break the -150 magnification lenses 4, 5 and 6 in holders 24 and 25 are lt Supply t h 30 motop P.B6 3, th -12 b tt l thfi Optical P For X magnification 1611868 completes a circuit from the -150 volt supply to PB7-3, 5 and 6 in lens holders 23, 24 and 25 are in the optical 3 4, 247, 7 5 through diode 3 and 1 to the P 12 motor, lens No. 4 is therefore driven out of the The holders are moved individually y slow speed optical path and actuates M16 to break the 150 volt motors connected to leadscrews and lead nuts on the Supply t th 12 motor d t f h travel of h holders; holder 25 being driven by motor 225 connected h ld Th N 5 d N .6 lenses h id h t0 leadscrew 235 and driving 163d nut holder 24 proper light-convergence angle for the 6X magnification. being driven y motor 224 Connected to leadscl'ew 234 Condenser lenses 7 and 8 are fixedly mounted in rotatand driving lead nut 244; and motor 223 connected to leadi b l 94; l 3 b i mounted above l 7, screw 233 and driving lead nut 243. Each lens holder is maintained in a vertical position by bearings 236 mounted Projectzon lens movement thereon which straddle a rail 237. Lens holders 25, 24 The four projection lenses are selectively moved into and 23 actuate microswitches M17, M15 and M13 respecthe optical path by three volt AC. motors mounted tively when the lenses are in the optical path and actuate on the projection turret '33. Motor 211 drives stub sha'ft microswitches M18, M16 and M14 respectively when they 212 to which lens 3 is connected. Motor 214 drives are not in the optical path. A table showing the relation stub shaft 215 to which lens 6X is connected, Motor between the motors, lenses, microswitches and magnifica- 217 drives stub shaft 218 to which lenses 12 and 30X tion is as follows: are connected. Four pushbuttons mounted on the con- Magnification 3X 6X 12X 30X Aux. Condens. Lens No None 5, 6 4, 5, 6 3, 4, 5, 6

OPTICAL PATH 6X Motor In .M17}Lenses 5 & 6 ..{Unactuated Actuated Actuated Actuated.

.Out... Ml8 Actuated Unactuated Unactuated Unactuated. 12X In M15}Lens4 {Unactuated Uuactuated- Actuated..-

Actuated. Out. M16 Actuated. Actuated Unactuated Unactuated. 30X Motor ..{Iu .M13}Lens 3 .{Unactuated Unactuated Unactuated Actuated.

Out 14 Actuated Actuated Actuated Unactuated.

trol panel control the movement of the projection lenses.

The correlation of the various magnifications with the pushbuttons on the control board and the switches in the functional diagram are as follows: 3 is PB4-2, 6 is 'PB52, 12 is PB6-2, 30x is PB7 2. Each of the pushbuttons are mechanically mounted so that each pushbutton will stay in the in position upon depression and all of the pushbuttons are interlocked so that depression of one button releases the previously depressed pushbutton. The movement of the projection lenses in the projection turret in changing from the 30X position to the 12X position is as follows:

At the 30X magnification the condition of the microswitches of the projection turret shown in FIGURES 22 and 5 is as follows:

M12Actuated M11-Unactuated M'-Actuated M6--Actuated M9-Unactuated M5Actuated Depressing pushbutton PB6-2 unlatches PB72 and latches PB62. The hot side of the 115 volt A.C. line is connected to the l2 -30 motor 217 through PB6-2 and the 12X tmicroswitch (M7). The motor begins to turn the 12 30 arm 36, 37 clockwise to move the 12X lens into the optical path. The 12 30 motor 217 continues running until M7 is actuated, at which point the 12X projection lens is in the optical path.

The operation of the projection lens turret in changing from 12X to 30X magnification is as follows:

The condition of the microswitches of the projection turret in FIGURE 22 is as follows:

M12Actuated M8Actuated M1'1Unactuated M7Actuated M10Actuated M6Una'ctuated M9-Unactuated M5Unactuated Depressing pushbutton PB7-2 unlatches PB6-2 and latches PB7-2. The hot side of the 115 volt A.C. line is connected to 12 -30 motor 217 through PB7-2 and the microswitch M5. The motor begins to turn the 12 X- 30X arm '36, 37 counter-clockwise to move the 30x lens into the optical path. The 12 -30 motor continues running until M5 is actuated, at which point the 30X projection lens is in the optical path.

In operating the projection lens assembly from the 30X to the 6X magnification, the operation and the condition of the microswitches is as follows:

M12Actuated M8-Unactuated 1Unactuated M7Unactuated M10A'ctuated M6-Actu ated M9Unactuated M5Actuated When switching from the 30X or 12X magnification to either the 6x or 3 magnification, the 30x or 12X lenses, which are both attached to inverted V arm 36, 37 move to an intermediate position where neither lens is in the optical path. In this position none of the microswitches associated with the 12 -30 inverted V arm are actuated. (That is M7, M8, M5, and M6 are unactuated.) Also, in a change from 30x to 6x (or from 6x to 30X) the lens leaving the optical path moves first. This sequence prevents the 6X and 12 lens arms from bumping each other during the switching. Depressing PB5-2 (the 6X pushbu-tton) unlatches PB7-2 and latches PB52. The hot side of the 115 volt A.C. line is connected through switch PB7-2 and M6 to the l2 -30 motor. The l2 -30 lens arm moves and releases M6 and stops at an intermediate position. When M6 is unactuated, the hot side of the 115 volt A.C. line is then connected through M6, and M9 to the 6X motor which then begins to move the 6 lens clockwise into the optical path. This motion is stopped when M9 (the 6X microswitch) is actuated.

Each of the projection lenses may be moved into the M8--Unactuated M7Unactuated optical path in any sequence of operation of the manual magnification pushbuttons on the control panel.

Fine focusing The apparatus here includes a fifth means for mounting the projection lenses for movement on the optical path to and from the film plane for fine focusing the film image upon the screen. Fine focusing is accomplished by mounting film turret 33 for vertical sliding movement on frame members 38 and 42 suspended from the top frame members of the apparatus. Turret slide rail 191 interlocks with guide 192 mounted on frame member 38 and slide rail 193 interlocks with guide 194 mounted on frame member 42 for permitting vertical motion.

Reference FIGURE 22. Raising and lowering of the turret is controlled from a finger engageable focus switch 196 which is connected to a Volt DC. gear reduced motor 197. Movement of switch 196 in one direction applies 1l5 v. through diode D13 and R11 to motor 197, and movement in the other direction reverses the direction of the motor by applying +115 v. through diode D14 and R11 to motor 197. Motor 197 rotates cam 198 which moves lever 199 by means of cam follower 201. Lever 199 is pivoted at point 202 and connected to the turret by link 203. Spring 204 connected to frame member 206 and the turret provides a counter balance.

Film drive Another feature of the present device is the capability of variably moving the film at each magnification by the operation of a minimum of hand operated controls located conveniently on a control panel adjacent the viewing screen. 7

The film drive mechanism for moving the film across the optical path consists briefly of a supply reel 30 for a length of film to be viewed and a motor drive 50 therefor; a take-up reel 31 for the film and a motor drive 51 therefor, the reels being mounted on a film transport 54 for guiding the film in a plane across the optical path; drive control means for selectively and variably energizing the take-up reel motor drive and supply reel motor drive for driving the film at varying speeds forwardly and backwardly; tension control means selectively energizing the motor drive for automatically applying tension on the film in either driven direction of the film; first switch control means for selectively determining the direction of rotation of the take-up reel motor drive when energized by the tension and drive control means; and second switch control means for selectively determining the direction of rotation of the supply reel when energized by the tension and drive control means; the switch means permitting operator selection for viewing the film emulsion side up or down.

The motors for the reels are here 24 volt D.C. printed circuit electric motors having a maximum speed of approximately 3300 rpm. and are standard items manu factored by Photo Circuits Corporation, Printed Motors, Inc. Motor 50 is connected to drive spindle shaft 52 by a gear reducer means 49, and motor 51 is connected to drive spindle shaft 53 by a separate gear reducer means 59.

Tension is applied to the film by providing a separate electrical circuit to the printed circuit motors for selectively variably energizing them for applying tension on the film in either driven direction of the film.

First switch control means here consists of a reverse toggle switch S12 electrically connected to the take-up reel motor 51 and the second switch control means consists of a toggle switch S13 electrically connected to the supply motor 50. The switches are located adjacent their respective motors so that the operator in loading the film can pre-select the direction of the motor drives so that film can be shown either emulsion side up or emulsion side down from the supply to the take-up reel regardless of how the film is wound on the .reel. Switch 

